TY - JOUR A1 - Fortmann, Mats Ingmar A1 - Dirks, Johannes A1 - Goedicke-Fritz, Sybelle A1 - Liese, Johannes A1 - Zemlin, Michael A1 - Morbach, Henner A1 - Härtel, Christoph T1 - Immunization of preterm infants: current evidence and future strategies to individualized approaches JF - Seminars in Immunopathology N2 - Preterm infants are at particularly high risk for infectious diseases. As this vulnerability extends beyond the neonatal period into childhood and adolescence, preterm infants benefit greatly from infection-preventive measures such as immunizations. However, there is an ongoing discussion about vaccine safety and efficacy due to preterm infants’ distinct immunological features. A significant proportion of infants remains un- or under-immunized when discharged from primary hospital stay. Educating health care professionals and parents, promoting maternal immunization and evaluating the potential of new vaccination tools are important means to reduce the overall burden from infectious diseases in preterm infants. In this narrative review, we summarize the current knowledge about vaccinations in premature infants. We discuss the specificities of early life immunity and memory function, including the role of polyreactive B cells, restricted B cell receptor diversity and heterologous immunity mediated by a cross-reactive T cell repertoire. Recently, mechanistic studies indicated that tissue-resident memory (Trm) cell populations including T cells, B cells and macrophages are already established in the fetus. Their role in human early life immunity, however, is not yet understood. Tissue-resident memory T cells, for example, are diminished in airway tissues in neonates as compared to older children or adults. Hence, the ability to make specific recall responses after secondary infectious stimulus is hampered, a phenomenon that is transcriptionally regulated by enhanced expression of T-bet. Furthermore, the microbiome establishment is a dominant factor to shape resident immunity at mucosal surfaces, but it is often disturbed in the context of preterm birth. The proposed function of Trm T cells to remember benign interactions with the microbiome might therefore be reduced which would contribute to an increased risk for sustained inflammation. An improved understanding of Trm interactions may determine novel targets of vaccination, e.g., modulation of T-bet responses and facilitate more individualized approaches to protect preterm babies in the future. KW - preterm infants KW - immunization KW - vaccination KW - safety KW - mechanisms KW - resident memory T cells Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-324261 VL - 44 IS - 6 ER - TY - JOUR A1 - Fortmann, Ingmar A1 - Dammann, Marie-Theres A1 - Humberg, Alexander A1 - Siller, Bastian A1 - Stichtenoth, Guido A1 - Engels, Geraldine A1 - Marißen, Janina A1 - Faust, Kirstin A1 - Hanke, Kathrin A1 - Goedicke-Fritz, Sybelle A1 - Derouet, Christoph A1 - Meyer, Sascha A1 - Stutz, Regine A1 - Kaiser, Elisabeth A1 - Herting, Egbert A1 - Göpel, Wolfgang A1 - Härtel, Christoph A1 - Zemlin, Michael T1 - Five year follow up of extremely low gestational age infants after timely or delayed administration of routine vaccinations JF - Vaccines N2 - This study is aimed at detecting the rate of untimely immunization in a large cohort of extremely low gestational age neonates (ELGANs) of the German Neonatal Network (GNN) and at addressing risk factors for delayed vaccination and associated long-term consequences. We performed an observational study of the GNN between 1st January 2010 and 31st December 2019. The immunization status for the hexavalent and pneumococcal immunization was evaluated in n = 8401 preterm infants <29 weeks of gestation. Univariate analysis and logistic/linear regression models were used to identify risk factors for vaccination delay and outcomes at a 5-year follow-up. In our cohort n = 824 (9.8%) ELGANs did not receive a timely first immunization with the hexavalent and pneumococcal vaccine. Risk factors for delayed vaccination were SGA status (18.1% vs. 13.5%; OR 1.3; 95% CI: 1.1–1.7), impaired growth and surrogates for complicated clinical courses (i.e., need for inotropes, necrotizing enterocolitis). At 5 years of age, timely immunized children had a lower risk of bronchitis (episodes within last year: 27.3% vs. 37.7%; OR 0.60, 95% CI: 0.42–0.86) but spirometry measures were unaffected. In conclusion, a significant proportion of ELGANs are untimely immunized, specifically those with increased vulnerability, even though they might particularly benefit from the immune-promoting effects of a timely vaccination. KW - immunization KW - prematurity KW - trained immunity KW - long-term outcome Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-239592 SN - 2076-393X VL - 9 IS - 5 ER - TY - JOUR A1 - Beiss, Veronique A1 - Spiegel, Holger A1 - Boes, Alexander A1 - Scheuermayer, Matthias A1 - Reimann, Andreas A1 - Schillberg, Stefan A1 - Fischer, Rainer T1 - Plant expression and characterization of the transmission-blocking vaccine candidate PfGAP50 JF - BMC Biotechnology N2 - Background: Despite the limited success after decades of intensive research and development efforts, vaccination still represents the most promising strategy to significantly reduce the disease burden in malaria endemic regions. Besides the ultimate goal of inducing sterile protection in vaccinated individuals, the prevention of transmission by so-called transmission blocking vaccines (TBVs) is being regarded as an important feature of an efficient malaria eradication strategy. Recently, Plasmodium falciparum GAP50 (PfGAP50), a 44.6 kDa transmembrane protein that forms an essential part of the invasion machinery (glideosome) multi-protein complex, has been proposed as novel potential transmission-blocking candidate. Plant-based expression systems combine the advantages of eukaryotic expression with a up-scaling potential and a good product safety profile suitable for vaccine production. In this study we investigated the feasibility to use the transient plant expression to produce PfGAP50 suitable for the induction of parasite specific inhibitory antibodies. Results: We performed the transient expression of recombinant PfGAP50 in Nicotiana benthamiana leaves using endoplasmatic reticulum (ER) and plastid targeting. After IMAC-purification the protein yield and integrity was investigated by SDS-PAGE and Western Blot. Rabbit immune IgG derived by the immunization with the plastidtargeted variant of PfGAP50 was analyzed by immune fluorescence assay (IFA) and zygote inhibition assay (ZIA). PfGAP50 could be produced in both subcellular compartments at different yields IMAC (Immobilized Metal Affinity Chromatography) purification from extract yielded up to 4.1 mu g/g recombinant protein per fresh leaf material for ER-retarded and 16.2 mu g/g recombinant protein per fresh leave material for plasmid targeted PfGAP50, respectively. IgG from rabbit sera generated by immunization with the recombinant protein specifically recognized different parasite stages in immunofluorescence assay. Furthermore up to 55 % inhibition in an in vitro zygote inhibition assay could be achieved using PfGAP50-specific rabbit immune IgG. Conclusions: The results of this study demonstrate that the plant-produced PfGAP50 is functional regarding the presentation of inhibitory epitopes and could be considered as component of a transmission-blocking malaria vaccine formulation. KW - PFS25 KW - plastid targeting KW - plant-made vaccines KW - agroinfiltration KW - gametes KW - sexual stage KW - plasmodium falciparum KW - membrane KW - antibodies KW - immunization KW - RTS,S/AS01 malaria vaccine KW - recombinant proteins KW - cost-effectiveness KW - purification Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-137327 VL - 15 IS - 108 ER - TY - JOUR A1 - Prelog, Martina T1 - Differential Approaches for Vaccination from Childhood to Old Age JF - Gerontology N2 - Primary prevention strategies, such as vaccinations at the age extremes, in neonates and elderly individuals, demonstrate a challenge to health professionals and public health specialists. The aspects of the differentiation and maturation of the adaptive immune system, the functional implications of immunological immaturity or immunosenescence and its impact on vaccine immunogenicity and efficacy will be highlighted in this review. Several approaches have been undertaken to promote Th1 responses in neonates and to enhance immune functions in elderly, such as conjugation to carrier proteins, addition of adjuvants, concomitant vaccination with other vaccines, change in antigen concentrations or dose intervals or use of different administration routes. Also, early protection by maternal vaccination seems to be beneficial in neonates. However, it also appears necessary to think of other end points than antibody concentrations to assess vaccine efficacy in neonates or elderly, as also the cellular immune response may be impaired by the mechanisms of immaturity, underlying health conditions, immunosuppressive treatments or immunosenescence. Thus, lifespan vaccine programs should be implemented to all individuals on a population level not only to improve herd protection and to maintain protective antibody levels and immune memory, but also to cover all age groups, to protect unvaccinated elderly persons and to provide indirect protection for neonates and small infants. KW - immunosenescence KW - aging KW - T cells KW - B cells KW - immunization KW - vaccination KW - thymus KW - influenza KW - neonates KW - antibody Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-196602 SN - 0304-324X SN - 1423-0003 N1 - This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively. VL - 59 IS - 3 ER - TY - THES A1 - Bahlo, Angela T1 - Immunisierungsstrategien gegen Prionenerkrankungen und Untersuchungen zur Prionen-induzierten Neurodegeneration T1 - Immunization strategies to prevent prion diseases and mechanisms of prion-induced neurodegeneration N2 - Prionenerkrankungen oder Transmissible Spongiforme Enzephalopathien (TSEs) sind übertragbare Krankheiten, zu denen die Creutzfeldt-Jakob-Krankheit (CJD) beim Menschen, Scrapie bei Schafen und die Bovine Spongiforme Enzephalopathie (BSE) bei Rindern gehören. Der infektiöse Erreger (PrPSc) besteht dabei aus einer abnormalen Form des zellulären Prion-Proteins (PrPC) und unterscheidet sich von dieser nur in der Proteinstruktur. Ein Hauptproblem bei der Entwicklung von aktiven Immunisierungsstrategien gegen Prionenerkrankungen besteht in der fehlenden Reaktion des Immunsystems auf das ubiquitär exprimierte Selbst-Antigen PrPC, welche auf einer Immuntoleranz gegen das körpereigene Protein beruht. In dieser Arbeit wurde ein transgenes Mausmodell für aktive Immunisierungsexperimente verwendet. Diese transgenen Tiere exprimieren Hamster-PrPC (HaPrP) unter der Kontrolle des Neuronen-spezifischen Enolase-Promotors (NSE) ausschließlich im Nervensystem auf einem Prnpo/o-Hintergrund. Durch die Verwendung eines „artfremden“ Proteins (rekombinantes Maus-PrP) gegen endogenes Hamster-PrP als Vakzine sollte die Immunogenität des Proteins verstärkt werden. Zusätzlich wurde für die Immunisierungen ein Fusionsprotein aus Maus-PrP und einem T-Helferepitop des Tetanustoxins (P30) eingesetzt. Als Adjuvanz diente das bakterielle DNA-Motiv CpG-1826, welches die Fähigkeit besitzt T-und B-Lymphozyten direkt zu stimulieren und die Sekretion von Interleukinen zu induzieren. Die Immunisierungen erfolgten subkutan und wurden monatlich durchgeführt. Nach jedem Boost wurden die Blutseren auf Antikörper sowohl gegen Maus-PrP als auch gegen Hamster-PrP untersucht. Neben der Analyse der humoralen Immunantwort mittels ELISA, Westernblot und FACS, wurden die Seren der immunisierten Mäuse auf ihre Fähigkeit getestet, die Prionenreplikation in vitro zu inhibieren. Mit der gewählten Immunisierungsstrategie war es mit beiden Proteinen möglich, hohe Antikörperantworten sowohl gegen Maus- als auch gegen Hamster-Prion-Protein zu induzieren. In Zellkultur waren die Seren in der Lage, signifikant den PrPSc-Gehalt zu reduzieren. Die immunisierten Mäuse wurden mit Hamsterprionen infiziert, um den Einfluss der induzierten Antikörper auf den Verlauf der Krankheit zu untersuchen. Nach Immunisierung mit PrP-P30 zeigten die Mäuse gegenüber mit Ovalbumin-behandelten Kontrolltiere eine signifikant verlängerte Inkubationszeit von ca. 30%. Im Gegensatz dazu konnte nach Immunisierung mit PrP ohne das zusätzliche T-Helferepitop keine Verlängerung in den Inkubationszeiten beobachtet werden. Abschließend wurde die Immunantwort in den immunisierten Tieren auf zellulärer Ebene mittels Proliferationsanalyse von T-und B-Lymphozyten untersucht. Dafür wurden Lymphozyten aus Milz und Lymphknoten der immunisierten NSEHa-Prnpo/o_Mäusen isoliert, ex vivo mit Maus-PrP bzw. Hamster-PrP stimuliert und auf die Proliferation von CD4-positiven oder CD8-positiven T-Lymphozyten untersucht. Durch die Analyse wurde gezeigt, dass es nach Immunisierung mit rek.PrP oder PrP-P30 zu keiner spezifischen Proliferation von T-Lymphozyten kam. Die beobachtete humorale Immunantwort scheint also unabhängig von einer spezifischen T-Zell-Immunantwort zu wirken. Die vorliegenden Ergebnisse zeigen, dass es möglich ist, durch die Wahl von geeigneten Immunisierungsstrategien, die Toleranz gegen das Selbstprotein PrP zu brechen. Sie stellen eine Grundlage für weitere Forschungsansätze dar, um prophylaktische Immunisierungen gegen Prionenerkrankungen in Zukunft zu realisieren. In einem weiteren Teil der Arbeit wurde die Funktion der apoptotischen Faktoren BAX und BCL-2 in der Prionen-induzierten Neurodegeneration in vivo untersucht. Dazu wurde neuroektodermales Gewebe aus BAX-/- und BCL-2-/- -Embryonen in das Gehirn von PrP-Knockout-Mäusen (Prnpo/o) transplantiert. Diese PrPC-defizienten Tiere sind nicht mit Prionen infizierbar und können PrPSc nicht propagieren. Nach Langzeitinfektion mit Mausprionen wurden die Transplantate histochemisch auf Prionenpathologie untersucht. Die typischen neuropathologischen Veränderungen waren dabei strikt auf das PrPC-positive Transplantat begrenzt. Zusätzlich wurden die Transplantate auf apoptotische Veränderungen untersucht und dabei TUNEL-Färbungen und aktivierte-Caspase-3 Färbungen durchgeführt. Es zeigten sich hierbei hinsichtlich Ausprägung und Stärke der Pathologie keine Unterschiede zwischen den BAX-bzw. BCL-2-Knockout Transplantaten und wildtypischen Transplantaten. Daraus konnte gefolgert werden, dass in diesem Modell weder BAX noch BCL-2 eine signifikante Rolle bei der Prionenpathogenese spielen. Die Ergebnisse aus diesem Teil der Arbeit leisten einen wichtigen Beitrag für das bessere Verständnis der durch Prionen-induzierten Neurodegeneration und sind für die Entwicklung von potentiellen therapeutischen Strategien hilfreich. N2 - Transmissible spongiform encephalopathies (TSEs) are a group of fatal neurodegenerative disorders that affect animals as well as humans (Prusiner, 1997). The most prominent are Creutzfeldt-Jacob disease (CJD) in humans, bovine spongiform encephalopathy (BSE) in cattle, scrapie in sheep and goats and chronic wasting disease (CWD) in cervids. These diseases are characterized by the conversion of the cellular prion protein (PrPC) into the abnormally folded isoform termed PrPSc, which accumulates and represents the major component of infectious prions (Aguzzi and Polymenidou, 2004). The development of an effective PrP vaccine has been hampered by immunotolerance to the ubiquitously expressed endogenous PrPC and the immunization with recombinant PrP led only to weak antibody-responses against the protein in wildtype mice. Here, we tried to circumvent this problem experimentally by generation of anti-PrP immunity in hamster transgenic mice. These mice (NSEHa-Prnpo/o) express Hamster-PrP under the control of the neuron-specific enolase Promotor (NSE) exclusively in the nervous system on a Prnpo/o background (Race et al., 1995). To further enhance the immunogenic feature of the mouse Prion-Protein, we fused a T-Helper epitope of the tetanus toxin (P30) to the C-terminal end of the protein (Panina-Bordignon et al., 1989). This epitope has been successfully in the development of several anti-tumour vaccines (Hertz et al., 2001; Steinaa et al., 2008). For the immunization the recombinant mouse Prion-Protein (PrP) as well as the fusion construct, called PrP-P30, was used. The bacterial DNA-Motif CpG-1826 was co-injected as an adjuvant, known as a direct stimulator of T-and B-cells and to have the ability to induce the secretion of interleukins (Krieg, 2002). The immunization was performed monthly and the sera were analysed after every boost for the presence of antibodies against Mouse- and Hamster-PrP. Beside the analysis of the humoral response via ELISA, Westernblot and FACS, the sera of the immunized mice were tested for their ability to inhibit prion replication in vitro. With the selected immunization strategy it was possible to induce a high antibody response both against Mouse-PrP as well as against Hamster-PrP. In the cell culture assay with prion-infected cells a significant decrease of the PrPSc level was observed. Furthermore the immunized animals were inoculated with Hamster prions to assess the efficiency of the induced antibodies to prolong the incubation time of the disease. With the introduction of the T-Helper epitope P30 it was possible to prolong the survival time of the treated animals about 30%, in comparison to the animals receiving only PrP without P30 or control animals, which were treated with Ovalbumin, respectively. A second group of transgenic mice was immunized to investigate the cellular immune response by proliferation assays. Towards this, lymphocytes of spleen and lymph nodes of the immunized animals were isolated and stimulated ex vivo with either mouse- or hamster-PrP. This analysis showed that the induced humoral immune response was independent of T-cells, because no specific proliferation of neither CD4- nor CD8-positive T-cells could be observed. In conclusion, the results clearly demonstrate that the possibility to break the self-tolerance against PrP by using appropriate vaccination strategies. It therefore might open a new avenue for the future development of prophylactic prion vaccines. In a second part of the work, the role of BAX and BCL-2 in prion-mediated neurodegeneration was characterized in vivo. BAX- and BCL-2- deficient neuroectodermal tissue was transplanted into the brain of Prnpo/o recipient mice. Mice devoid of PrPC (Prnpo/o) are resistant to prions and do not propagate the infectious agent (Bueler et al., 1993). After long-term infection with mouse scrapie prions, typical histopathological features of the disease, such as gliosis, spongiosis and PrPSc accumulation were examined with histochemical techniques in the engrafted brains and the pathological changes were restricted to the PrPC-expressing neurografts. Furthermore we perform TUNEL and active-Caspase 3 stainings for determination and detection of apoptotic changes in the neurografts. Regarding the strength and characteristics of prion pathology no differences were seen between BAX- and BCL-2-Knockout grafts in comparison to the wildtype tissue. In summary, these results demonstrate that neither BAX nor BCL-2, two major players of apoptosis, are necessary for prion-induced neurodegeneration. These results therefore contribute to a better understanding of the pathogenic mechanisms in prion diseases and are useful for the development of future therapeutical strategies. KW - Impfung KW - Apoptosis KW - Immuntoleranz KW - Prionen KW - Immunisierung KW - Neurografts KW - prions KW - immunization KW - tolerance KW - neurografts KW - apoptosis Y1 - 2008 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-28443 ER -